Imager system for non-destructive profile read-out

Abstract

A method and apparatus for obtaining a profile read-out of an object in a field of view of a solid-state imager without destruction of the image data at the imager. In an application using a CID imager, X-axis and Y-axis projections of the array are obtained by sensing charge transfer from sequentially addressed columns into all rows simultaneously followed by sensing charge transfer from sequentially addressed rows into all columns simultaneously. Calculation of centroid and area of an image can be obtained without the necessity of reading out each pixel.

I claim: 
     
       1. In a solid state imager having a matrix of individual picture elements arranged in rows and columns, each of the picture elements including a first and a second conductive plate, each of the first conductive plates in each row being connected to a common row electrode and each of the second conductive plates in each column being connected to a common column electrode, read out of the signal in any one picture element being effected by charge transfer between the first and the second conductive plates, a method for obtaining a profile of an object within a field of view of the imager comprising the steps of: A. Selecting a first row for data readout;   B. setting a bias voltage on all rows other than the selected row to preclude charge transfer in such other rows;   C. setting a voltage on all column electrodes to create a potential well at each second conductive plate;   D. changing the bias voltage on the selected row such that charge under each first conductive plate in the selected row is transferred to the potential well created at the corresponding second conductive placte;   E. summing the charges appearing on the column electrodes resulting from the charge transfer to thereby obtain a signal representative of the profile along the selected row; and   F. repeating steps A through E for each of the row electrodes whereby a profile is obtained along the axis of the rows.   
     
     
       2. The method of claim 1 and including the additional steps of: G. Selecting a first column for data readout;   H. setting a bias voltage on all columns other than the selected column to preclude charge transfer in such other columns;   I. setting a voltage on all row electrodes to create a potential well at each first conductive plate;   J. changing the bias voltage on the selected column such that charge under each second conductive plate is transferred to the potential well created at the corresponding first conductive plate;   K. summing the charges appearing on the row electrodes resulting from the charge transfer into the potential wells created under the first conductive plates to thereby obtain a signal representative of the profile along the selected column; and   L. repeating steps G through L for each of the column electrodes whereby a profile is obtained along the axis of the columns.   
     
     
       3. In a object recognition system of the type including a solid state imager having a matrix of picture elements arranged in rows and columns, a data processing system connected to the imager, the data processing system including a memory for storing data and further including comparing means for comparing stored data to data received from the imager, a method for identifying objects comprising the steps of: A. Storing in the memory a profile characteristic along X and Y axes of ideal characteristics of an object of the type to be identified;   B. imaging an object to be identified on the solid state imager;   C. reading directly from the imager the summation of all picture elements in each of the rows and of the columns;   D. generating a profile characteristic of the object to be identified using the summation of picture elements; and   E. comparing the stored profile characteristics to the generated profile characteristic to identify the object.   
     
     
       4. In a solid state imager having a matrix of individual picture elements arranged in rows and columns, each of the picture elements including a first and a second conductive plate, each of the first conductive plates in each row being connected to a common row electrode and each second conductive plates in each column being connected to a common column electrode, readout of the signal in any one picture element being effective by charge transfer between the first and the second conductive plates, apparatus for obtaining a profile of an object within a field of view of the imager comprising: A. means for sequentially selecting a row for data readout;   B. means for setting a bias voltage on each non-selected row to preclude charge transfer in such non-selected rows;   C. means for setting a voltage on all common electrodes to create a potential well at each second conductive plate;   D. means for changing the bias voltage on the selected row such that charge under each first conductive plate is transferred to the potential well created at the corresponding second conductive plate; and   E. means synchronized with said selecting means for summing the charges appearing on the column electrodes resulting from the charge transfer between said first and second conductive plates to thereby obtain signals representative of the profile along the row axis.   
     
     
       5. The apparatus in claim 4 and including: F. means for sequentially selecting a column for data readout;   G. means for setting a bias voltage on each non-selected column to preclude charge transfer in such non-selected columns;   H. means for setting a voltage on all row elecrodes to create a potential well at each first conductive plate;   I. means for changing the bias voltage on the selected column such that charge under each second conductive plate is transferred to the potential well created at the corresponding first conductive plate; and   J. means synchronized with said column selecting means for summing the charges appearing on the row electrodes resulting from the charge transfer between said second and first conductive plate to thereby obtain signals representative of the profile of the object along the column axis.   
     
     
       6. The apparatus of claim 5 wherein said profile readout is non-destructive and including means for sequentially reading each individual picture element in said array to obtain a composite representation of the object. 
     
     
       7. The apparatus of claim 6 and including means for selecting groups of picture elements for individual read-out based upon data obtained during the profile readout.